The present invention relates to an anti-theft fastening for articles of merchandise for use with article surveillance or identification tagging.
Goods on sale in retail outlets such as department stores generally carry anti-theft tags which must be removed from purchased articles at the point of sale. If an attempt is made to remove an article from a store without the tag being removed, the tag, which contains electrical circuitry, triggers an alarm system at an exit of the store.
An anti-theft tag must meet certain requirements. It must be inexpensive, must not be susceptible to removal by a would-be shoplifter whilst being easily removable at a point of sale counter with a special tool, and should not damage any article during attachment and removal of the tag to and from the article. This is particularly important with clothing which is susceptible to damage.
U.S. Pat. No. 3,911,534 describes one form of fastening clip for articles of clothing. The clip has a pin which passes through the fabric of the article and is clamped in a female component, the fabric of the article being secured between the pin head and the female components. The female component has retaining balls which are loosely received in lateral bores in a retainer which in turn is slidably received in a housing. The retainer is biased towards the pinhead by a spring such that the balls contact a frusto-conical inner surface of a ring rigidly secured in the housing and are urged against the pin shank, gripping the latter and preventing withdrawal of the pin. Release of the pin is effected by drawing the retainer away from the pin head using a special tool, thus releasing the balls and the pin shank.
Whilst fastening clips such as the above-described clip are relatively inexpensive and do not damage the article material, they do suffer from a severe disadvantage. It has proved easy to disengage the pin from the female component, for example by giving the end of the female component remote from the pin head a sharp rap. Although this projects the housing towards the pin head, the inertia of the retaining balls and the retainer momentarily result in these being displaced relative to the housing away from the pin head, releasing the grip on the pin shank and allowing the pin to disengage from the female component.